Multiple stage torque converter drive



Jan. 5, 1965 o. K. KELLEY 3,164,034

MULTIPLE STAGE TORQUE CONVERTER DRIVE Original Filed Dec. 11, 1947 9Sheets-Sheet 1 I O. K. KELLEY MULTIPLE STAGE TORQUE CONVERTER DRIVE Jan.5, 1965 original Filed Dec. 11, 1947 9 Sheets-Sheet 2 Jan. 5, 1965 O. K.KELLEY MULTIPLE STAGE TORQUE CONVERTER DRIVE 9 Sheets-Sheet -3 OriginalFiled Dec. ll, 1947 ga/a Bnvcntor Jan. 5, 1965 o. K. KELLEY MULTIPLESTAGE TORQUE CONVERTER DRIVE 9 Sheets-Sheet 4 Original Filed Dec. l1,1947 Jan. 5, 1965 o. K. KELLEY 3,154,034

MULTIPLE S'I'AGEy TORQUE CONVERTER DRIVE Original Filed Dec. ll, 194'? 9Sheets-Sheet 5 Jan. 5, 1965 o. K. KELLEY MULTIPLE STAGE ToRQuE CONVERTERDRIVE 9 Sheets-Sheet 6 original Filed Dec. 11, '1947 PQQN.

Jan. 5, 1965 o. K. KELLEY 3,164,034

MULTIPLE STAGE TORQUE CONVERTER DRIVE Jan. 5, 1965 o. K. KELLEY MULTIPLESTAGE: ToRQuR CONVERTER DRIVE 9 Sheets-Sheet 8 Original Filed Dec. l1,1947 Jan. 5, 1965 o. K. KELLEY 3,164,034

MULTIPLE STAGE TORQUE CONVERTER DRIVE Original Filed Dec. ll, 1947 9Sheets-Sheet 9 0W APL-'VERSE INVENTOR.

@my fr@ ATTORNEY United States Patent O 3,164,034 MULTIPLE STAGE TRQUECONVERTER DRIVE Oliver Kenneth Kelley, Birmingham, Mich., assigner tGeneral Motors Corporation, Detroit, Mich., a corporation of DelawareContinuation of application Ser. No. 790,950, Dec. 1l, 1947. Thisapplication hiay 24, 1954, Ser. No. 431,868 88 Claims. (Cl. 74-732) Theinvention relates broadly to a combination of fluid torque converter andgear drive mechanism which provides a range of conversion of torquethrough a hydraulic torque converter, and provides for uninterruptedchanging of the driving torque `of the associate gear mechanism by iluidpressure means. This application is a continuation of Serial No.790,950, filed December 11, 1947, now abandoned.

The invention relates more specifically to arrangements of such fluidtorque converters with gearing, wherein the fluid torque converters yareof a type which has an eective operation cycle ranging from maximumtorque multiplication to substantial 1-to 1 drive; and to thecombination of such torque converters with change speed gearing, whichlatter is arranged to be changed under torque by iluid pressureactuation and control means.

It pertains further to special iluid pressure devices which yarecoordinated with ratio selection controls for such drive assemblies,which devices not only provide inherent timing of the shift intervals;but also provide means to regulate the driving torque of plural ratios,which means respond to the degree of torque during interratiotransitions.

The invention further pertains tothe utilization of plural pump fluidpressure supply means controlled for providing uid pressure to both lthetorque converter and the gear change mechanism, and in which the supplymeans are automatically effective for Iall of the required operations ofthe assembly under all drive conditions.

It likewise pertains to the type of drive controls for such devices -ashave been named above, in which there is .a single ratio controloperated by the operator, and capable of establishing any availableforward or reverse drive ratio by simple motion from one station toanother, all other controls being wholly automatic.

A primary object of the invention is to provide a fluid torque convertercombined with a gear train which shall have a full range ofuninterrupted torque output under all driving ratios, and including fulltorque and maximum performance operation in the ranges determined by thechange of gears of the gear assembly for Iall of the driving rangesabove an initial predetermined speed and torque. A further object oftheinvention is to provide a gear train driven by the torque converter andhaving fluid pressure actuated ratio changing mechanism effective fordirect forward drive, low ratio range drive, and for reverse drive; theuid pressure actuated mechanisms being supplied by constantly availableline pressure, automatically maintained, and controlled by a singlevalve, manually selected.

An additional object is to provide a fluid pressure supply system forthe aforesaid constructions which likewise maintain a positive pressurein the working space of the torque converter, while maintaining throughthe same, a steady flow of fluid which is traversed through a coolerdevice, the flow continuing under all drive conditions.

It is likewise an object of the invention to utilize pressure controlvalving which automatically maintains the flow of lluid to the torqueconverter working space, while simultaneously maintaining steady linepressure for the operation of the fluid pressure ratio actuating system.In this connection it is a sub-joined object to control the magnitude ofthe ratio actuation pressure by a change of selected speed ratio, suchthat the available pressure for lilii Patented Jan. 5, 1965 iceperforming the iluid pressure lactuation operations will be varied inproportion to the degree of torque multiplica.- tion required.

Another object is the provision -of special valve means and mechanismwhich shall be responsive to the degree of torque during upshift anddownshift ratio changes, and which introduce la dynamometriccharacteristic for providing smooth torque shifts under all change ofdrive operations.

A further object is the utilization of accumulator valve mechanism forthe purpose of regulating the shift timing interval of all forward drivespeed ratio changes.

In previously known constructions in which the fluid drive is obtainedby bladed turbine devices known as lluid torque converters, it has notbeen known to placesuch converter-s between the source of driving powerand a speed change gearing unit which afforded full torque shift. ln thecase of gear units shown in prior art Iarranged in series with a primarydrive torque converter, it has been necessary to unload the drive insome manner for the change of gear ratio, this process resulting indwell inte-rval losses, as well as jerky transitions tending to shockthe drive mechanism and cause discomfort to the driver and passengers.The present invention avoids these dithculties by first utilizing aspeci-al form of torque converter which is capable :of delivering fulltorque acceleration from maximum reduction to substantial 1tol drivewithout interruption, and second, by utilizing a special form oftorque-regulated gear ratio shift system which inherently controls thetransfer of torque from one forward drive ratio to the other by deviceswhich measure not only the degree of existing torque, but [also whichestablish a predetermined degree of torque overlap during the drivechange intervals. The result of this combination is a drive assemblyhaving units which inherently provide full ranges oi torquemultiplication, with full capability of change between said rangeswithout surges of torque which could be noticed as shock accelerationsor decelerations during the shift intervals. In other words, thecombination stated above permits the car driver to accelcrate fromstandstill to full speed in either forward drive gear range, or toinitiate acceleration in one range and shift to the other during theacceleration interval. In practice, with the motor car engines of thepresent day, this combina-tion enables the car driver to obtain maximumperformance when needed, without the inconvenience of performing anymanual operation other than movement of a ratio control handle from onestation to another. For ordinary use this stated shift of the controlhandle has been found unnecessary, and the lower range of speed ratioaiiorded, is used only for emergency low range drive purposes. It shouldbe noted however that where the ultimate acceleration performance of thedrive equipped with this invention is demanded, such is available. Thecontrol hand-le also serves as a parking brake controller.

The gear train used herein in the combination is believed to possesssome elements of novelty although the general form is thought t0 be old.As will be understood further the gear train is equipped with a drivingsun gear and a reaction sun gear which are clutch coupled for 1- to-ldrive of the output connected carrier. The driving sun gear meshes witha long planet which is meshed with a short planet, the latter meshingwith the reaction sun gear. An annulus gear meshing with the shortplanet is braked for establishing reverse gear drive, while the reactionsun gear is braked for 10W forward drive. This train is supportedagainst rocking couples by a bearing sleeve carried on the reactionannulus gear and bearing against the adjacent cylindrical face of theoutput carrier. The compact gear arrangement enables the 4clutchmechanism to be compartmented adjacent the gearing and s,1 einensupported by web extensions of the casing through which the controllingfluid pressure is fed. As will be understood further the gear and clutchassembly is compartmented separately from the huid torque converter,with supply pump passages connected through a casing web section betweenthe converter and gear unit compartments. The construction providesunusual rigidity and exact alignment, While permitting space forconverter uid passages, and the controls. A second web extension of thecasing assembly at the rear Iof the gear unit is formed to house a pumpwhich supplies the fluid pressure system when the vehicle is movingforward.

The web extensions of the casing between the converter and gear unitcompartments likewise provide reaction support for one-way brakes andprevent the backward rotation of a plurality of stators of the torqueconverter.

The torque converted consists of iive bladed elements located so thatthe impeller is in the outflow zone of the working space, the driventurbine rotor is in the inflow Zone, the two rotatable reaction rotorsare in the inner radial zone bridging inflow with outflow, and the fifthbladed element is an auxiliary impeller located in the radially inwardportion of the outflow zone adjacent the second of the two reactionrotors. The reaction rotors are prevented from backward rotation by 1waybrake devices, and the auxiliary impeller is connected by a l way clutchto the main impelier so that the auxiliary impeller may run forwardlyfaster than the main impeller. This converter provides a full scale ofuninterrupted drive from initial maximum torque multiplication to 1-to1` drive between input and output, which in combination with the changegear unit equipped with full-torque shift actuation and controlfacilities, gives a wholly new drive acceleration from standstill to1-to-1 drive, in which the range of ratio may be changed at any time.

Further advantages, novelties and new and useful results appear in thefollowing description and attached drawings which represent one exampleof the invention herewith, in which:

FIGURE 1 is a longitudinal section of a drive mechanism embodying oneform of the invention.

FIGURE 2 is a part section taken at 2-2 of FIG. 1 looking forward or tothe left in FIG. 1.

FIGURE 3 is a similar section taken at 3 3 of FIG- URE 1.

FIGURES 4, 5 and 6 show the stages of operation of a special controlvalve arrangement for'the coordination and timing of the ratio shifts inthe gear unit of the linvention.

FIGURES 7 and 8 are schematic diagrams of the structure shown in FIG. 2and should be compared with FIGS. 9 and 10 which represent the end-pointoperation of a special control valve arrangement which responds to bhedegree of torque for controlling the ratio shift interval.

FIGURE 1l -is a schematic section of a iuid pressure regulator valveshown in FIG. 2, and explained further in connection with FIGS. 12 to14.

FIGURE 12 is a schematic diagram embodying the subject matterof FIGS. 4to 11 specifically, and cornbined with the servo operating mechanism ofFIGS. 1, 2 and 3. The diagram also shows the complete pumping system,and the gear shift control valving, with the parts stationed Iin theirlow gear drive positions. Pressurized conduits are shown in full lines.Dash lines indicate vented conduits.

FIGURE 13' is like FIG. 12, but shows the parts as stationed forproviding reverse gear drive.

' FIGURE 14 is similar to FIGS. 12 and 13, but shows the parts stationed,for establishing direct drive by the gear units of the assembly.

FIGURE 15 is a sectional view taken at L15-l5 of FIG. 1 to show themanual controls for the gear shift valving and for the parking brake.

FIGURE 16 represents the arrangement of the fluid outflow passages fromthe converter and cooler, em-

d bodying the pressure control valving shown schematically in FIGS. 12to 14.

FIGURE 17 is a separate showing of the shift control valve of FIGS. 12to 14 for the purpose of indicating its operating connection with thestructure of FIG. l5, and to show its neutral drive station.

FIGURE 1S is a representation of one of the one-way brake mechanismsshown in FIG. 1, the part section being taken at iti-18.

FIGURE 19 is an elevation View of portions of the gear box and steeringcolumn as viewed from the left of FIG. 15, showing the external controllinkage for the operator.

FIGURE 2O is a partly sectional view of the control mechanism located onthe steering column of a vehicle, and including the mechanism at thelower end of the steering column which provides control of the poppetstations for setting the mechanism of FIG. 19 accurately.

FIGURE 2l is a cross sectional view through the mechanism of FIG. 2O toshow the poppet control mechanism.

FIGURE 22 is a view of the mechanism of FIG. 20 showing the controls asseen by the vehicle driver.

FIGURE 23 is a simplified diagrammatic showing of the transmission shownin FIG. 1, being the upper half of a symmetrical longitudinal sectioncorresponding to FIG. l, and

FIGURE 24 is a schematic transverse section of the complete gearingtaken on the line 24-24 of FIG. 23.

FIGURE 1 is a vertical longitudinal section taken through thetransmission assembly 4of the invention, to show the relative positionsof the parts and units. The vehicle engine is located at the left, anddrives a uid torque converter generally designated W, which is arrangedto drive the output shaft di) through a two-speed and reverse planetarygear unit of a somewhat novel nature.

The forward portion of the assembly including the torque converter iscontained within the housing little, and the gear portion within thesecond housing tltl con* tinuous with the first, and the output shaft 69within the rear end section lidd.

The engine crankshaft 1l has a iiange bolted to a flexplate or fly-wheel2 which is bolted to a front cover 3 of a drum 4 acting as a containerfor the converter unit W. The drum 4 comprises the shell or backingmember for the blades 5 of the impeller I of the converter, whichdeliver circulating liquid to the blades '7 of the output rotor orturbine G. A separate impeller rotor la having its blades 6 locatedinward radially from the blades S has its hub 112 attached to the outerrace 1S of a one-way clutch and the race I8, with inner race 19 attachedto drum 4, provide a channel for one-way clutch members 2?. Blades 6 areheld in core section 105. The outer race 1S is provided with cam slotsset at an angle with respect to the direction of rotation as shown inthe example of FIG. 18, such that the auxiliary impeller la may rotateforwardly faster than the primary impeller I, but never slower than thelatter.

The working space of the converter W is completed by two reaction rotorsR1 and R2 having blades at 8 and 9, the rst of which receives iluid fromthe rotor O, delivering same to reaction wheel blades 9, which latter inturn deliver the fluid to the auxiliary impeller Ia having blades 6. Aradial web 10de is bolted between housing sections 108C and i60, and iskeyed to a cylindrical sleeve 13 splined to an inner lrace member 1S. Anouter cam member lo is attached to reaction rotor R1, and the outer cammember 17 is attached to the reaction rotor R2. One-way brake lookinDmembers 14 lie between the members 1S and 16, and the one-way brakemembers 14 lie between member 1S and outer member 1'7. These one-waybrakes prevent backward rotation of the reaction rotors Rl and R2 but topermit free forward rotation thereof.

The output rotor O is mounted on a hub l() which is splined to thecentrally located shaft 11, which is supported in a piece 12a fixed tothe flywheel 3 and supporting pilot bearing 12. The shaft 11 constitutesthe output or driven shaft of the torque converter, and the input ordriving shaft of the gearing. It extends to the right where it issplined to sun gear 27, and to clutch hub 43.

The torque converter W shown here is of the general type disclosed inLetters Patent to Allan Coats, U.S. 1,760,480, issued May 27, 1930, butdiffers therefrom in certain important respects, the differencesresiding in the blade and rotor arrangement, in the relative operatingranges of circumferential uid velocity and toroidal velocity, and in theuse of an auxiliary impeller Ia lway clutched to the main impeller I toreceive the outflow of the second reaction wheel R2, and in otherparticulars.

The shell 106 and core section 102 support blades 7 of rotor O on hub10. The hub 110 and core section 103 support blades 8 of rotor R1. Thehub 111 and core section 104 support blades 9 of rotor R2. Blades ofimpeller I are supported in core section 101 and drum d. The fluidworking space lies outside elements 101 to 105 and inside elements 4,106, 110, 111 and 112.

The detail of FG. 18 corresponds to the 1-way clutch or brake structuresof FIG. 1. The cam slots of member 18 are directionally taken so thatrace 18 may overrun while rollers 20 idle.

Pumps P and Q are provided for maintaining the working space of theconverter W lled at all times during its operating cycle, and forproviding servo pressures required to actuate the torque establishingdevices or speed ratio-determining elements of the gear unit, to bedescribed further. n

The front pump P is supported by the radial portion of the part 100e,against which is tted the pump body 22 and plate 2251, properly formedto accommodate the driven pump gear 24 and the driving pump gear 25 xedto an axial extension of race piece 19 which is bolted to the drum 4.The pump construction shown in FIG. 1 is inherently adapted to deliver aquantity of liquid which is proportional to the number of rotations ofthe engine, as is known in the art. The ported plate 100e is locatedbetween the housing sections 100 and 100C, being formed into an axialsleeve 23 which surrounds a portion of the shaft 11. The pump passagesand conduits of the system will be described further in detail. The seal21 is located between an axially extending portion of the pump body 22and the axially extending portion 19 of the drum 4.

The rearl pump Q is assembled in the joining web of casing sections 100and 10M, the pump assembly comprising three portions 110', 111' and 112.The portion 110 is a ported plate forming an endwall, the portion 111 isrecessed and provides a housing and bearing for the driven gear 113, themeshing driving gear 114 being keyed to shaft 60. The ported cover plate112 completes the assembly, and is bolted to the endwall of casingsection 100. The pump suction spaces connected to suction main 115 opento the sump 115 thru strainerI 116 to be described later. The rear pumpdelivers liquid at a rate measured by the forward speed of rotation ofthe output shaft 60.

The dashed arrows leading from space 23b of front pump end plate 100eindicate the ow of oil from pump P to the converter Working space, thepassage 168 leading between members 13 and 19. The oil ows radiallyoutward between the hub 111 of rotor 9 and the l-Way clutch 18-19-20,and enters the space between the blades 6 of the auxiliary impeller Iaand the blades 9 of the second reaction rotor R2. Here the oil isaccelerated into the circulatory flow, and a portion of the oil bodyescapes at the outer radial parting zone, to ilow into the spaceradially outward of, and to the left of turbine output member O,restrained between cover plate 3, drum 4, and the back of rotor shell106. Another portion escapes between 7 and 8.

Oil is extracted from the working space stream, radially inward of thespace between cover plate 3 and turbine member O, thru passage 10 in hub10, flowing inward at the right of hub 10, and along the space externalof shaft 11 inside the axial portion of non-rotating casing element eand sleeve 13 and from thence radially outward by delivery passage 165for connection to the ow control system of FIG. 17.

The gear unit G is made up of carrier 2S attached to or integral withshaft 60 and having a double set of meshing planets 30 and 31 supportedon separate spindles 32 yand 33 respectively, vcarrier 28 having web 28bat the left. r1`he planets 30 extend to full width between the radialportions of the carrier 2S and mesh internally with the input sun gear27, and with the planets 31 as indicated in the upper part of FIG. 3. Asecond or reaction sun gear 35 is meshed with the planets 31 and itattached to a radial web 36 of a drum 37 which is splined internally toaccommodate clutch plates 40. The left portion of the drum 37 has aradial flange terminating in an inner sleeve which extends axially tothe right, and is fitted with the keyed ange 41 acting as a springretainer. The internal clutch plate hub 43 is splined to shaft 11, andis externally splined to acommodate plates 45, which mate with clutchplates 40. A clutch presser piston 14 is mounted to slide inside thedrum 37, being fitted with seal members 46 and 47, and is normally heldto the left by clutch release spring 48, which bears against thepreviously described flange 41. As will be understood furthertiuidpressure may be admitted at the left in cylinder 49 between the radialWall of the drum 37 and piston 44 to engage clutch plates 411-45 forestablishing direct drive between shafts 11 and 60 by locking togetherthe sun gears 27 and 35.

The drum 37 is surrounded by a brake member 50 so that it may be heldagainst rotation and cause the sun gear 35 to stand still; this elfectrequiring the planet pinions 31 to roll around the sun gear 35 when theinput sun gear 27 is rotated.

Therefore, when brake 50 is actuated, the shaft 11 drives the shaft 60at low gear ratio.

Surrounding the planet gears 31 is a meshing annulus gear 38 attached todrum 51 supported on a bronze ring 51a bearing on a cylindrical face ofcarrier 28. The annulus gear 38 and drum 51 are surrounded by a brake5.5 for stopping the drum and annulus gear 38 to establish reverse geardrive between the shafts 11 and 60.

The rear portion of the gear box has the shaft 60 supported 1n the websof sections 100, and 100d. The shaft 60 is splined for small speedometergear 61 and for universal joint coupling sleeve 62. Leakage of oil from100d is prevented by a seal of the universal joint connection housing,not shown.

As described to this point, the engine drives the torque converter W,which in turn drives the gear unit G, which determines one ofthree'driving conditions for shaft 60; namely, low range, high range, orreverse gear drive.

FIG. 2 is a sectional View taken across the transmission to the right ofthe parting line between the housing sectlons 100e-100 at 2 2. This viewis given to relate the fluid control system to the remainder of thestructure, and to .show the fluid pressure passages connecting the workumts, the fluid working space of the converter, the valving, theaccumulators, and the pumps P and Q.

In this view the structures of the regulator valve 150 and the reactiontorque measuring valve are shown. FIGS. 9-14 show their hydraulicconnections.

FIG. 2 shows a section of the actuating system for the low brake member50. The ends of the member 50 are formed into bosses 52 and 53, theanchor boss 52 being notched at 76 for anchor strut 54. A lever 75 ispivoted on a shaft 75 mounted in casing 100 and bears againsttorque-responsive anchor Valve 130 and is notched at 74 for the adjacentend of the strut 54. The apply end 53 of band 50 is notched at 72 forapply strut 80 seated in notch 78a of apply lever 7S pivoted on shaft 78mounted in the casing.

The apply lever 7S is fitted with an adjustable stud 73 which is notchedfor the end of piston rod 71, the latter being surrounded by releasespring 77 and xed to piston 70.

The housing itil) is formed to provide the apply cylinder 69 for thebrake actuating piston 70. The brake releasing spring 77 serves torelease the band 50 from the drum 37 except when i'luid pressure isadmitted to cylinder 69.

Passage 79 is for admission of tluid pressure from the hydraulic controlsystem tothe cylinder 65.

A somewhat similar arrangement is provided in FIG. 3 for` the operationof the reverse brake 55, the section being taken at 3'3 of FIG. l. Brakemember end bosses 56 and 57 are provided. The apply boss S7 is notchedat 87 for an'actuating strut 88 operated by a lever 91. The anchor boss56 is notched at 83 for anchor member 84 supported by a strap 81 whichis looped around the pivot pin 9i'. The lever 91 has adjustment stud 85notched at S6 for piston rod 39. Piston 9i) in cylinder 92 is xed to rod89, and is held in brake-releasing position by spring 9S except Wheniluid pressure is supplied to cylinder 92 by passage 148s.

Application of fluid pressure in cylinder 92 to the head of piston 9i)causes the piston to travel upward against spring 95 to exert a thruston the lever 91 to move strut 88, which forces the movable band end at57 to the right to clamp band S on drum 51.

This motion compresses the release springs 95, which permit the inherentresilience or" the band to release the brake when the fluid pressureunder the head of piston 9i) is removed.

Actuating pressure for loading the plates 4Q, 45 of the direct driveclutch fill-45 of FIG. 1 is supplied by passages connecting the outputof the pumps P and Q thru control valving las diagrammed in FIGS. 12 to14, to cylinder space 49 inside drum 37 to move annular piston 44against spring 48.

FIGURE 18 is a typical part section of one of the onevvay clutches orbrakes used in the torque converter WV. The external cam plate member 16is representative of any one of the three outer members lr6, 17 or i8 inFIG. l, and the inner member may be either of inner races 1.5 or 19. InFIGURE 18 these are num-bored as i7, for the outer member, and 15 forthe inner member, the locking members in the present instance beingrollers 14 which are loaded against slip by plungers 14n, springs 14band spring retainers 1de. As Will be understood, the part section ofFIGURE 18 is a view looking aft from the front of the transmission.

In the toothed gear unit G, the driving sun gear 27 meshes with the lowrange planet gears Sil, and the reversing planet gears 3l mesh with boththe reaction sun gear and the reversing annulus gear 38.

l-l drive is obtained by applying uid pressure to clutch piston 44causing plates ttl-45 to lock the unit.

Y Reverse is obtained by holding annulus gear 3S with brake S5.

Low gear is obtained by holding sun gear 35 and drum 37 with brake 50.

The direct drive clutch dll-45, the low brake Sil-37 and the reversebrake -51 are all friction couplings or friction torque-establishingdevices having friction elements which when engaged establish torque orcomplete a driving connection between the driving or input shaft l1 andthe driven or output shaft 60. Each of the friction torque-establishingdevices is actuated by a servo in the form of a variable volume fluidpressure chamber Which constitutes an expansible chamber motor whichestablishes torque in the friction device which, as is known in the art,is measured by the pressure in the chamber. Low pressure in the chamberengages the friction elements lightly, which may be termed partialengagement in which condition they are capable of transmitting only lowtorque bcyond which they Slip. Rate or" increase of pressure in thechamber determines the rate of increase of torque in the rictiontorque-establishing device. Maximum or full pressure in the chamberengages the friction elements with maximum or full torce, which may becalled full engagement, in which condition they transmit full torque.

Shifts into loW and into direct drive are controlled accurately bytiming and coordinating devices which assure lhat there will not be anysudden lurches of torque, so that he vehicle operator may move the ratioshift controller lor the valving at will, and obtain an extremely smoothratio change under all driving conditions. This control system utilizesa mechanism which responds to the instant torque conditions, and appliesa corrective factor to the servo pressure delivery lines involved.

Should the engine fail to start, towing or pushing the vehicle enablesthe rear pump Q to supply the hydraulic system requirements, as will beunderstood further.

The master regulator valve l5@ of FIGS. 2, ll, and l2 to 14 constitutesa pump-selector valve which vents or unloads the front pump, causing itto idle after the rear pump Q reaches sufficient speed to supply thesystem. This shift from P to Q may occur normally between l0 and 40miles per hour. Each pump is equipped with Check valves CV and CV', FIG.l2, respectively to prevent back flow when either pump is not providingits Working pressure. Reference to FIGS. l2 to 14 will show therelationship of the pump feed lines.

In the position immediately following, the separate elements and groupsof the servo pressure system are first individually discussed.

The l to l drive clutch cylinder 49 has a given volumetric capacity,requiring filling before final engagement with a finite quantity of oil.To malte final engagement Smooth, the oil is first admitted rapidly tothe cylinder 49 to eiect partial engagement oi' clutch plates 453-45quickly. Then, in response to predetermined movement of the plates, orto partial engagement, which is signalled by abrupt increase of pressurein the cylinder d'9, the ow is slowed, in order to build up fullpressure and full torque slowly or gradually. This is accomplished withthe aid of an accumulator enclosing a piston 26) which is also apressure-responsive valve connected to the clutch cylinder feed lineZilli, shown in FEGS. 4 to 6, and 12 to 14.

In the initial stage of engagement of the clutch, the parts are as shownin FIG. 4. The servo oil feed passage 2d?. admits clutch servo oilaround the neck of dump, check, or pilot valve 203, the oil flowingfreely and rapidly thru fast port 26d, fast ilcxv valve passage 2.@5 andfast How port 286 to the passage 261, connected to the clutch cylindere9 of FIGS. l and l4.

The bleed holes or restricted orifices 2?? and 268 in the valve 2%permit small quantities of oil to liow out above and below the valve203.

When clutch actuator piston 44 meets the resistance of plates atl-45, inFIG. l, there is a rapid rise of pressure, effective throughout conduit261 and in the communicating space above valve 2li@ tending to shift thevalve 2th? from the position of FIG. 4 downward against spring 299 tothe FIG. 5 position.

The rate of increase of pressure in the clutch chamber 49 is reduced bythe expanding volume into which the line 232 discharges oil, whichexpanding volume is effected by movement of the accumulator Wall formedby the piston Zut). During this movement the upper land on the pistoncloses the by-pass around the orice 2l7, that is the fast flow passageformed by the piston groove 2&5 between large port Ztl@ and clutchpassage Zilli. The clutch passage Zilli is now connected with thepressure feed 2%2 only thru the slow-.flow passage formed by small bleedhole 297 in the top of valve 203, which provides a slower pressurebuild-up on the clutch piston 4A; as the spring 299 is 'furthercompressed by valve 260.

When the back pressure in passage 2G31, which is to say in the clutchchamber and in the accumulator, equals pump or line pressure, the clutch40-45 is fully engaged, and valve 200 is at its lowermost point withspring 209 fully compressed, even lower than positions shown in FIGS. or6.

When the control valving for pressure passage 202 is connected toexhaust, outflow from clutch passage 201, bleed hole 207, and from thespace below check valve 203 thru bleed holes 208 begins. Since therelief of the small volume of oil under valve 203 thru 208 occurs morequickly, the force of spring 209 on piston valve 200 exerted on the oilbody overcomes the resistance of valve spring 211, causing valve 203 tomove down to the FIG. 6 position, and open a second fast-How passage Safor rapid release of the clutch. The valve 200 may now move upward toits former position of FIG. 4, urged by spring 209, and valve 203likewise returns to the position of FIG. 4.

The operational results of this combination of accumulator and dumpvalves are rapid clutch cylinder filling, gradual clutch engagement, andrapid relief for disengagement.

The above type of operation is likewise provided by a secondcombination, of the same description as shown in FIGS. 4 to 6 inclusive,for the brake 50, operating in the same manner, but not identical indimensions of parts or spring force values. The diagram arrangement ofFIGS. l2 to 14 shows both of the accumulator-and-dump valvecombinations, one for the direct drive clutch control as in FIGS. 4 to6, and the other for the control of the pressure which operates brake 50for establishing the low gear range. The corresponding numbers are primenoted for the latter.

A special provision for further correlating the action of the low gearband 50 and the clutch 40-45 is disclosed. This enables the shiftbetween low and high range to be made with particular smoothness, and aminimum of torque slip.

The diagram of FIG. 7 represents the structure of FIG. 2, and shows thelow band 50 engaged by struts 54 and 80, the strut S0 being moved bylever 78 and piston 70 of cylinder 69. The strut 54 is similarly held ina notch of lever 75 and in engagement with the end of the valve 130pressed against the lever 75 by spring 132. Valve 130 may be termed ananchor valve.

Whenever band 50 is actuated to grip drum 37 by piston 70 the torsionaldrag moves the band in the direction of drum rotation, the force of thereaction tending to move valve 130 against spring 132 as shown in FIG. 8to provide a form ott dynamometric measuring device.

The diagrams of FIGS. 7 and 8 show by the arrows the action described.When the tluid pressure on piston 70 is relieved, and the band 50released, the torque reaction force compressing the anchor valve spring132 disappears, the valve returning to the FIG. 7 position.

The detail of the porting of anchor valve 130 is shown in FIGS. 9 and10. The casing section 100b is bored for the valve 130 which has aprojecting end 1300L, and three bosses a, b, and c. The hollow interioraccommodates spring 132 and is vented at 13011. As will be explainedbelow, the bosses or lands a and b collectively constitute valve meansresponsive to torque reaction on the brake for controlling maintenanceof pressure in the low apply cylinder 69 when the transmission isshifted from low to high, and the land or boss c is valve means whichopens and closes the connection between conduits 139 and 143 whichtogether constitute ia by-pass around the high accumulator mechanism.

The central port 13011 connects on the right to the passage 133connected to passage 79 for the cylinder 69 of the brake 50, forestablishing low gear drive.

The upper port 134 is connected to passage 135 leading from the shiftcontrol valve 230 of FIGS. 12 to 14. The lower port 136 is joined topassage 141 from the relay port 236 near the right end of the shiftvalve 2304 The 10 port 138 is joined to passage 139 connected to primaryclutch feed line 202 of FIGS. 12 to 14. Port 142 connects thru passages143, and directly to the clutch cylinder 49 of FIG. l.

The lower gear servo feed lines 135, 133, 141 and the direct driveclutch :feed lines 143, 139 are effectively routed thru the porting ofthe anchor valve 130 so that the valve response to reaction torquefurnishes a regulatory control both on the application of clutch 40-45land low band 50.

Upon shift into low as determined by the shifter valving of FIGS. 12 to14, the anchor valve 130 is first positioned as shown in FIGS. 7 and 9,in its upper position, until there is mechanical drag induced by lowgear drive reaction between band 50 and drum 37, which forces the valve130 to move against spring 132 to the lower position of FIGS. 8 and 10,i-n which position port 134 is closed by the boss a, ports 13017 and 136are connected, and ports 138 and 142 are connected. The low servopassage 133 is now fed thru the ports 13301; tand 136 by relay passage141 from the positioning of control valve 230. The valve 130 is down inthe FIG. 10 position during the drive torque interval of low gear, andmay only rise momentarily under high speed coasting conditions.

When the valve 230 of FIGS. 12 to 14 is shifted to the direct drive feedposition, under torque, ,the feed to port 136 by line 141 continueswhile the feed by line 135 to port 134 is exhausted at port 234 of valve230.

Pressure from line 141 thru ports 136, 13012 thru line 133 maintains theholding force on the low gear actuator piston 70.

Pressure from shifter valve port 231 in valve 230 is fed by line 202land line 139 to port 138 of Valve 130, thru port 142 to line 143, .toprovide a direct `feed of pressure into the clutch cylinder 149. Tlhisprovides quick filling of the clutch cylinder to initiate the`assumption of the torque by the clutch plates, so that a conditionexists in which no funther torque is carried by the low reactiongearing.

As the clutch plates 40-45 are loaded by piston 44 the force of torquereaction on the band 60 falls off, since the clutch plates now sustainan increasing fraction of the torque load. Valve 130 therefore is movedupwardly to the posi-tion of FIG. 7, by the torque-reaction measuringspring 132.

This is the critical point of the torque reversal in the shift. Theclutch holding power must be built up to a higher value so that theengine may be decelerated or pulled down tto sa speed commensuratel-to-l ratio, without a noticeable surge in the delivery of torque.

When the spring 132 has move valve 130 up a given distance, the waive130 opens the port 130b and passage 133 tot exhaust thru pont 134 andline 135 via the shifter valve 230, releasing pressure from the brakecylinder 69. This releases band 50. At this point the valve 130 hasblocked communication between ports 142 and 138, which interrupts therapid filling which had been going on thru line 143. Further clutchfilling now proceeds, feeding thru the orice 207 of valve 203 asdescribed in connection with FIGS. 4, 5 and 6. After this action theplates 40-45 are fully engaged under full pressure and the shift todirect has been controlled on a basis of exactly measured torquereaction, with the torqueoverlap action itself as the master controlforce. By this process, the engine cannot run away, and there is nolurch or bump in the overall drive of shaft 60.

When the shift control valve 230 of FIGS. 12 to 14 is moved to establishlow, the anchor valve 130 is moved from the position of FIG. 9 to thatof FIG. 10 thru the inverse sequence of flow control operations, thetiming action being substantially the same for smooth transfer fromdirect coupled gear torque to reduction torque reaction.

The action of the master pressure regulator valve of FIGS. 2 and 11should be studied before dealing with i l the overall control operationsof the diagrams of FIGS. 12 to 14.

This valve determines whether the system is supplied from front pump P,rear pump Q, or both, and in addition is a relief valve for determiningthe maximum pressure of the front pump When it alone supplies the system1and the maximum pressure of the system when supplied by both pumps orby the rear pump alone. Provision is made for changing the range ofpressure, that is increasing'the maximum value of the pressure of thesystem, when the gearing is shifted either to low or reverse. Therefore,each pump P and Q in combination with the regulator valve 156constitutes a source of iluid under limited maximum pressure forsupplying the control system, land has means for changing the maximumpressure with change of torque requirements. The source thus providesone range of control pressure for high, and a different range for lowand reverse.

Referring to FIGS. 2 and 11-14, .the valve 15h is litted in a bore ofcasing 199k, and has an end portion d of relatively small diameter, andthree bosses e, f, and g of relatively large diameter. The end d isloaded by spring 144 in space 145 connected by passage 146 to the valve23) of FIGS. 12 to 14.

Low speed boost port 147 connects to passage 143, front pump supply port1419 to front pump feed passage 151 which connects to the front pumpinlet inside the front pump check valve CV, pont 152 to the sump 115'whichconstitutes the inlets of both pumps, converter supply port 153 topassages 23h, 168 leading to the Working space of the converter W, andinlet port 15.5 is joined to line 156 connected to the pressure deliveryspace of the pumps P 'and Q between the check valves CV and CV.

Valve 15d determines the ratio shift actuation pressure, and controlsthe shift of pressure supply from the front pump P to rear pump Q. Bleedhole 157 connects the spaces on either side of boss g.

When there is no pressure in the line 156, which indicates that neitherpump is Working and therefore that the car is standing with the enginenot running, the spring 144 holds the valve stem fully to the right sothat land f of valve 150 closes the converter supply port 153 to preventloss of iiuid from the converter Working space. Rise of pump pressure inline 156 (FIG. 12) is communicated through opening 157 to the pressurearea formed by the right face of land g and this moves the valve stem tothe left against spring 144 so that the position of the valve stem is a.measure of the pressure. At a predetermined pressure the land g opensport 153 to lill the remaining converter space and build up the pressurein the converter. Since the pressure supply chamber connected to intakeport 155 is always connected to the main line 255, as shown by FIGS. 12to 14, the supply can be connected to any friction torque-establishingdevice at any time. A supply of liquid under pressure is thereforeavailable to operate any friction torque-establishing device beforeliquid can be supplied to the torque converter, and in fact unless thepumps are furnishing the required normal operating pressure the port 153is closed. This assures that there can be no flow to the torqueconverter which might inherently reduce'the pressure of the main linewhich would reduce the torque transmitted by the frictiontorque-establishing device until after the friction torque-estabiishingdevice is applied with its normal operating pressure to produce itsnormal operating torque.

At another predetermined pressure the stem of valve 15? moves to aposition slightly to the left of the position shown in FIG. 13 so thatthe land e cracks the port 149, which then vents to the sump any oiltending to proe Kil) capacity, the valve 150 has moved so that band eopens port 149 fully to connect the output line 151 of pump P to exhaustpart 152. For example, the pressure value at this stage could be poundspsi., entirely suliicient to operate the l to l drive clutch. Themaximum pressure of the rear pump is limited by land f which cracks theconnection between the exhaust port 152 and the space between lands 3and g and relieves excess dow to the sump.

For practical reasons, it is desirable to use a higher pressure foroperation of the low and reverse bands 5d and 55, therefore the forceurging the valve 15) closed is boosted by pressure in the passage 146and space 145 connected to the lowv servo valve port 235 of NGS. l2 to14, and operating on the pressure area of boss d; and for the sameeffect for reverse, pressure in passage 14S and port 14'? is appliedover the area of land e. This arrangement introduces an increasedresistance to the motion of the valve 156 toward relief at port 152,such that a higher pressure is developed in the servo feed lines 79 and148 before valve 15) can begin to relieve.

This higher level of pressure may be set at a value approximating 13Gpounds psi., by the design of the elements of the system.

In FlG. 2, the actual assembly detail of pressure regulator valve 169 ofthe fluid system is given as distinct from the schematic views of FIG.ll and FIGS. l2 to 14. The plate section lttg is bored for the valve 159and drilled for the porting, which is coordinated with the variouspassages of the uid pressure system. The section 11mg is fastened tohousing section 1001' by bolts or other convenient means, not shown. hevalve portions are assembled by means of cap screws. The portion d ofthe valve is used as a piston for assisting the springs 144 in low geardrive. Pressure supplied by line 146 acts on both sides of springretainer 144e: and is only effective on the end of d. The check valve CVis assembled in plate 166g and seats on plate 15u21 and is connected topassage 221 and passage Z22 for port 149. The oil flow from the frontpump P feeds thru CV and enters port 155 between bosses f and g, and itspressure is effective at the left of boss g thru bleed hole 157, tooppose the springs 144 and urge valve 156 to the right. Under a givenpressure and spring force, the port 153 connected to the converter feedlines 23h and 168, is exposed, as explained in connection With FIG. 1l.One result of this is that a predetermined pressure is maintained in themain line 225 and any servo connected to it, before the port 153 can beopened to supply the converter. vWhen boss f is shifted farther to theright in FIG. 2 to expose outlet port 152, the leakage to exhaustprevents the pressure from rising above a predetermined value.Reinforcing pressure for low gear and reverse band actuation is obtainedby the admission of pressure to ports 146 and 147 respectively, asdescribed further in connection with FIG. 11.

FG. 12 is to show the operating characteristics of the control systemfor drive in low upon actuation of low brake band 50.

One or both pumps P, Q may supply port 155 of valve connected to ports232 and 237 of ratio sln'fter valve 239, now rst described.

The shift control volve 231i' of FIGS. 12 to 14 and 17 is fitted in abore in casing section 161129, or a section adjacent thereto, and hasfour bosses l1, i, j and /c from left to right as shown. The casing isported at 231e, 231, 232, 233, 234, 235, 236 and 237 from left to right.

The port 231 is connected to direct clutch supply passage 202 jointed tothe inlet of the direct drive accumulator pilot valve 203, and topassage 139 and to port 138 of the low gear anchor valve 130.

The inlet port 232 and inlet port 237 are connected by main line 225 toport of the pressure regulator valve 150. Passage 155 connects port 155with the passage 22d forming the outlets of the valves CV and CV.

The reverse supply port 233 is connected by passages 148, 148:1 withcylinder 92 of lthe reverse band piston 90, and to reverse 'boat port147 of the pressure regulator valve 150.

Ports 231g and 234 are vents, leading to the sump.

The port 235 is connected by passage 135 with por-t 134 of the anchorvalve 130 of FIGS. 9 and 10, and also by passage 148 leading to space145 of the pressure regulator valve 150 of FIG. ll.

Port 236 connects by passage 141 with port 136 of the anchor valve 130of FIGS. 9 and l0.

In low, as seen in FIG. l2, the left branch of main line 225 is closedat port 232 by land and pressure is delivered from the right branch of225 from inlet port 237 to ports 235 and 236, the latter delivering topassage 141 and thru ports 136 and 130b of valve 130 to line 133, actingin 202' and 201 to hold accumulator valve 200 down, and in passage 79leading to cylinder 69 for holding the low gear band 50 of FIG. 2 thruthe force applied to piston 70.

The pressure of line 135 is cut off by boss a of valve 130 at port 134.Pressure in -the selector valve is conducted by line 146 to the leftwardface of boss d of valve 150, in space 145, to raise the line pressuremaintained by the regulator valve as explained above. As noted above,the anchor valve 130 is movable under torque reaction to regulate theloading interval for band 50 and clutch 40-45.

Feed -of pressure to maintain the converter (W) Working space filled isprovided by port 153, line 2312, meting orifice 223, and line 168.

Should road speed fall o, fall of line pressure maintained by the rearpump permits valve 150 to move to the right enough to close port 149 soas Ito introduce the pressure pump P to the line 156. But, when vehiclespeed is high enough, it will be noted that the effective line pressurein 226, 156 from pump Q will hold valve CV on its seat, while front pumppressure in lines 221, 151 is relieved thru port 149 to drain port 152between bosses e and f valve 150.

For reverse the valve 230 is placed as shown in FIG. 13 the boss kclosing input feed port 237, cutting off the feed to low supply ports235, 236, and pressure lines 135, 141 and 146, and venting lthem at port234. Land i cuts olf the left branch of main line 225 from clutch supplyport 231 and vents the clutch line 202 at port 2312,.

Pressure feed is delivered from passage 225 to port 232, across thevalve space between bosses z' and j to port 233 and to reverse servolines 148, 148a, taking effect through port 147 behind land e to augmentthe force of spring 144 on pressure regulator valve 150; and is exertedin cylinder 92 to actuate reverse band 55 of FIGS. l and 3.

As before, the converter W is maintained under pump line pressuresupplied by pump P thru check valve CV, line 156, port 155, line 23h,restriction orifice 223, and passage 168. The boss e of valve 150 closespor-t 149 and line 151 until the pressure of the front pump reaches itspredetermined maximum.

It should be remembered that when shaft 60 is driven vreversely, therear pump Q, revolving backwards, would tend to drain the passage 226,except for check valve CV', urged by pressure in line 226, as well as byits own spring -to close, permitting pump P alone to supply the system.

Reference is now made to FIG. 17 where the ratio control valve 230 isshown. In this view it will be noted that the valve is stationed to theright of the high ratio position of FIG. 14, that is neutral.

Upshift from low to high is accomplished by ratio control valve 230 tothe right from the position shown in FIG. l2, to that of FIG. 14. Thiscauses the pressure which had been actuating the lower gear band piston70 to be cut off at port 235 from line 135. The hand h cuts off exhaustport 231 and land z' connects port 232 to port 231, and line 202 leadingto valve 203, to deliver pressure to passage 201 and passage 140connected to cylinder 49 for actuating clutch piston `40. This pressureis also delivered to passage 139 and to passage 143, connected to ports142 and 138 of anchor valve 130.

This vents the low gear boost chamber 145 at exhaust port 234, restoringthe lower value of maximum pressure maintained by the regulator valve.Main line pressure is now supplied from the selector valve outlet port236 Ithrough line 141 and the depressed anchor valve 130 (FIGS. l0, l2)to line 133 and loW band apply servo 69 to retain the low band appliedtemporarily. When oil is supplied from the left-hand branch of the mainline 225 through outlet port 231 of the selector valve `to line 202which leads to -the high accumulator, it starts to apply the directclutch as described above. A branch 139 leads from the line 202 to port138 of the anchor valve 130 and out from the port 142 of the anchorvalve to a line 143 which by-passes the accumulator and connectsdirectly with the high clutch apply line 140.

As the direct drive clutch begins to take hold, it exerts more and moreforward torque on the clutch drum 37, which is also the low brake drum,and which up to now has been held stationary by the low band 50. Whenthe increasing forward -torque of the clutch 40-45 exceeds the reversereaction torque on 4the drum 37, the drum rotates the band 50 forward,which is counterclockwise asindicated by the arrow in FIG. 7, to releasethe torque valve to the position shown in FIG. 9. When this occurs thetorque valve connects to the low servo line 133 to line 135 which is nowvented at port 234 of the selector valve 230, as shown in FIG. 14. Thisrapidly dumps the low servo 69 and releases the low band. A-t the sametime the by-pass formed by lines 139 and 143 around the high accumulatoris cut off by the torque valve and pressure is gradually built up in theclutch, as described above, through the low-rate passage formed by theorifice 207 in the check or pilot valve 203 of the high accumulator.This leaves the transmission in high gear.

To shift from high to low the manual valve is moved from the position ofFIG. 14 to the position of FIG. 12 in which land h opens exhaust port231 to establish communication between port 231 and exhaust port 231aand dumps the high clutch through line 140, port 201, past the checkvalve 203, which fully opens instantly, and line 202. At the same time,oil is supplied to the low servo lines 141 and 135, as described above,so that the servo 69 begins to apply the low band. Between release ofthe high clutch and the l'inal full application of the low band there isa brief interval in which the transmission is not transmittingsubstantial torque. This allows the engine to speed up, as is customarywhen shifting to a lower speed ratio, or higher torque ratio. When theengine has speeded up to a point that lits car speed at the low ratiothe engine starts to rotate the reaction drum 37 backward and thisrotates the low brake band 50 to push the torque valve down. Thischanges the connections of the low band apply line 133 from line 141 toline 135.

The pumps P and Q supply iiuid pressure for the transmission shiftcontrols, the lubrication system, and maintain the converter (W) Workingspace under positive pressure at all times when either the engine isrunning or the car is moving forward. The master pressure regulatorvalve feeds the working space of the converter thru a meterinf orifice223 and when both the car and the engine stop, the land f provides acut-off action, to maintain the quantity of fluid in the converteragainst idle drainage to the sump 115', which is located below the levelof the converter.

Oil is supplied in the inter-rotor space, between the impeller blades 6and the stator or reaction member 9, and outflow from the couver-teremerges in the inner radial zone between the driven turbine rotor 7 andthe stator member 8. It is thought to be novel in this combination toadmit the input working space fluid at a point Where it is immediatelysubject to acceleration from a low to a high kinetic state. Theconverter rotation applies force alegrias to circulate this oil bodywithou-t exepnsive and complicated injector and ejector means, providingsufficient velocity of motion to guarantee rapid movement thru theexternally located coolers, yet avoiding fluid voids in the workingspace body by maintenance of positive pressure therein.

On the outflow side of this dynamic flow system, in the passage 165 arelocated two relief valves 21) and 211, the rstof which 210, is set torelieve at a given value,

V for example 50 p.s.i., its overow going by passage 212 to the secondrelief valve 211, which may be set -to relieve at a lower value, forexample p.s.i. The lS-pound space is connected by passage 213 to thetransmission lubrication spaces,y while the overow of valve 211 relievesto the sump.

FIG. 16 shows the relative positioning of the cooler or heatexchanger inthe uid system.

The cooler C receives oil under pressure from the converter workingspace in pipe 165 and delivers it to pipe 165. The valve 21) has aleakage hole 216 in its top center to permit a constant continuingquantity of flow toward the sump, and its upper face acts as a seallimited by the force value of spring 214. In a given design, thisspring-and-valve combination would be set to permit full outflow at port215 into space 212, under p.s.i., in line The valve 211 is exposed tothe pressure of space 212 and relieves by yielding of spring 217, tospill Ithe excess oil into the spent pressure passages 218 and 219 at apredetermined pressure, for example, of 15 p.s.i. The passage 213 leadsto the various lubrication channels for the converter and gearing, tomaintain same under positive pressure.

Orifice 223 serves to limit the amount of oil required by the torqueconverter so that the pump Q, which is of smaller capacity than pump P,can provide lthe system at a low car speed and relieve the larger pump Pto prevent loss of power.

The function of orice 223 of FIGS. l2 to 14 is to maintain a controlcirculation thru the converter W, avoiding excess flow thru the workingspace which `could generate churning losses, also.

The valve 210 set at a given pressure level maintains a static levelpressure in the working space of converter W, preventing cavitation. Thevalve 211 provides further staged regulation of the working spaceoutflow, and gives a convenient point from which to tap for lubricantflow to the running parts, at outlet 213.

FIG. 15 is -a part section taken at 15-15 of FIGURE l. The output shaft60 of the carrier 28 of the gear unit G is toothed externally at 176.The housing ltltld is formed to provide a compartment. In thiscompartment the lever 175 is fixed to a shaft 173, and is equipped witha ball joint 176 coacting with rod 176', ball-jointed to lever 177 onshaft 173, which lever is urged by the inward end of coil spring 185against the stop 184. The lever 171 is toothed to match. the teeth ofthe member 170, and may have one or more teeth. The lever 171 is rockedby arm 181which is pivoted to lever 179 supported in the housing by thesaid'shaft 178. The levers 179 and 177 are both xed to the said shaft178.

The lever 171 is pivoted at 172 to swing in an arc, to intersect theteeth when urged by lever 181, and swings toward the ring of teeth 170under clockwise rotation of lever 177.

The arrangement of the adjacent parts is clear by referrence to FIGS. 15and 17, also 19. The control shaft 173 carries arm 175y for operating anextension rod 198 forl valve 230 of FIG. 17.

The lever 174 actuates a parking brake by moving arm 171 into mesh withteeth 170. Should the tooth or teeth of 171 be rejected by movement ofmember 170, reaction motion of lever 174 indicates the fact to theoperator and also stores energy momentarily in the spring 135.

Rocking of lever 174 to slide rod 190 to shift valve 230 'iti of FIG. 17permits ball-jointed rod 17o to swing in a non-interfering arc with thelever 171 out of tooth contact with 17th.

The rod 19t) for moving valve 2.36 is operated by the mechanism of FIG.15 and is shown in FIG. 17.

The angular positioning of lever 174 and lever 175 with respect to theratio and parking controls corresponds with common poppet-positionlocating means in the linkage external to lever 174.

It is desired that the coordinating ratio valve and parking brakecontrol be clearly understood. In the sectional view of FIG. l5, theconstruction of the mechanical system for operating the parking brakedevice includes the toothed member 171i, splined on shaft 6l) to be heldfrom rotation by pawl 171 pivoted at 172 on the casing, and rockable tomesh With the teeth of member 17d.

The cross shaft 173 is operated manually by linkage connected toexternal lever 174, and swings lever 176 carrying ball joint element 17ofitted into the end of rod 176', ball-jointed to lever 177 on shaft 178.

Lever 1711 is pivoted on shaft 17 8, is pivoted at 189 to piece 181,which is pivoted in turn at 132 to the toothed lever 171.

Rocking of cross shaft 173 so that the pivot end at 1% of lever 175swings toward the eye of the observer causes rod 176 lto rise and swingthe pivoted levers 177, 179 and 181 so that the alignment of pivots 17S,180 and 132, in net effect, performs like a toggle, causing toothedlever 171 to move into solid registry with the teeth of member 170.Spring 185 coiled around the pivot 17S has a projecting end tending toreturn this mechanism to the positions shown in FIG. l5, with lever 177resting against stop 184.

The end of valve 230 of FIG. 17 is connected by rod to lever 175, sothat the overall ratio and parkingr brake control may be provided thrumotion of external lever 174.

It should be noted that the sequence of operations for the describedmechanism of FIGS. l5 and 17 transverses the valve 231B thru reverse,low, direct, neutral, and parking positions.

Rotation of the impeller I when rotor O is standing still forces the uidof the working space from the inner radial zone to the outer radial zoneof the converter, giving the fluid kinetic energy and forcing the iluidagainst the blades 7. The oil tends to flow around the section of thetorus counter-clockwise as FlG. l is viewed, and thru the reactionrotors R1 and R2, the auxiliary impeller la and to enter the interbladespaces of the impeller l', to repeat the sequence.

lf rotor O could rotate at the same speed as impeller l, there would beno llow. The magnitude of the toroidal flow is always proportional tothe differential of speed between O and I.

The core ring formed by the sections 161 to 105 guides the ow so as toavoid turbulence within the oil body, thus improving torque efficiencyby preventing local surges and eddies in the toroidal stream.

The flow of oil in causing rotation of output rotor O imparts torque tothe turbine output shaft 11. The reaction rotor blades 8 and 9 are soformed that the backward tangential component of ilow from the exit ofrotor blades 7 is reversed and converted to a forward velocity enteringthe blades of the impeller l.

The reaction rotors R1 and R2 are coupled by the l-way brakes 16-14-15,17-14-15 so that they cannot rotate backward, hence affording a fulcrummeans for the required reversal of the toroidal flow.

The kinetic energy remaining in the body of fluid delivered by thereaction rotors lto the impeller inlet spaces is absorbed by theimpeller blades to increase the energy eventually delivered by theimpeller to the output turbine O.

At high differential speeds, the toroidal flow being greatest, the netenergy so delivered is greatest, and the output rotor is at a lesserspeed than the impeller. The result is torgue multiplication, whichwould be at maximum when the output rotor would be stopped or nearlystationary, and the impeller would be driven at maximum speed by theprimary power source.

The reaction rotors R1 and R2 are capable of being driven forward whenthe reverse reaction forces applied by the toroidal ilow diminishes toZero.

The reaction blades S and 9 are given predetermined, differentangular-ities so that the rotor R1 reaches the zero torque point beforeR2, and rotates forwardly with output rotor O. The remaining reactionforces resulting from the differential speed relationship noted above,are then taken by the blades 9 of reaction rotor R2, until the reactionforce on R2 in turn, dies out, whereupon R2 begins to rotate forwardly.

The auxiliary impeller Ia has its blades, and the l-way clutch 18-19-20,so arranged that when the rate of toroidal flow is relatively high withrespect to the absolute speed of the impeller, the rotor Ia may rotateforwardly faster than the impeller I, and thereby relieve the flow of aportion of the losses. The rotor Ia spins forward freely during thedrive interval of high torque, its blades 6 guiding the toroidal flowinto the inlet zone of the impeller blades for avoidance of undesiredturbulence at high toroidal dow velocities.

These characteristics are merged so that an overall acceleration frommaximum torque multiplication to nearly l-to-l drive between shafts 1and 11 takes place. It should be understood that the drive combinationof the invention is particularly adapted for fluid torque converters ofthe type which have an operating range from reduction ratios thru arange of diminishing torque multiplication to nearly l-to-l coupledratio. In actual practice, one form of converter of the presentinvention may reach its minimum slip at vehicle speeds above 30 to 35miles per hour.

Reviewing the operating sequences, in the diagrams of FIGS. l2 to 14,the active pressure lines are shown in full line, and the inactive linesin dashed line. The front pump P is shown as driven by the part 4 ofFIG. l, and the rear pump Q driven by output shaft 60. In the lowercenter of these diagrams a single pressure feed pipe 156 is shownconnected to outlet passage 226 of both check valves CV and CV', and thelines 221 and 220 connect the pumps P and Q to the inlets of therespective check valves.

The upper leg 156 of the check valve outlet passage 226 is joined to theport 155 of the pressure regulator valve 151B. Passage 220 from the rearpump Q is connected to the inlet of the valve CV', the pumps operatingindividually or jointly to provide the system with fluid pressure underall drive conditions. Annular port space 149 of the valve is connectedby passage 151 leading from the outlet of the front pump only.

Pump Q supplies no pressure when the vehicle is stopped, and pump Pdriven by the engine, supplies pressure to unseat valve CV and admitpressure to passages 225 and 156.

The ratio control valve 23) has two pressure input ports 232 and 237,and vents at ports 23M in the open space to the left of land lz and atport 234. The delivery ports 235, 236 direct the fluid pressure toestablish low gear drive. Port 233 provides for reverse, and port 231provides 'direct drive. Port 15.3 supplies the working space pressurefor the converter W thru passages h and 168, and orifice 223.

Passages 141, 133, 79 supply the low ratio brake cylinder 69, andpassages 202, 139 and 140 lead to the direct clutch cylinder 49 betweenthe seals 46 and 47 inside the drum 37. Passages 148, 148a lead to thereverse brake cylinder 92.

FIG. 12 shows the low gear range drive position, and conditions of thesepressure control elements, FIG. 13 those for reverse drive and FIG. 14for direct. In these i bers.

15 diagrams the clutch feed line 140 is equipped with check valve 131for admitting air to the line Whenever the line 'is vented by the manualvalve 230; and a second check valve 137 is shown mounted in the clutchpiston 44, the latter relieving the oil which otherwise would betrapped, and under the action of centrifugal force would generatepressure causing the clutch to drag, should the clutch be disengaged athigh speeds of the clutch mem- Valve 137 is seated by pressure exertedby plates 411-45.

The linkage of FIG. l9pconnects the vehicle steeringcolumn control headfor the gear drive assembly with the cross-shaft 173 of FIGS. l and 15.1 i

Lever 174, outside, xed external of the casing, is fixed to shaft 173and is pivoted to rod 265 in turn pivoted to the long arm of abell-crank lever 264, pivoted on `the casing or frame construction. Theshort arm of the bell-crank lever 264 is pivoted to link rod 263 whichis ben-t at degrees into la pivot hole, in the arm 262 rotated bycontrol shaft 258 of FIG. 20.

The control shaft 258 is mounted inside the steering column 256 and hasonly rotational motion.

The shift control mechanism is arranged so that the driver by graspingthe handle 250 will know of the posi tional steps, and so that thedevices inside the gearbox will be always exactly stationed for theseveral ratio station positions. For these purposes poppet mechanism isprovided, to be operated by the rotation and axial motion of the maincontrol shaft 258.

The poppet mechanism of FIGS. 20 and 21 consists of carrier piece 259for spring-loaded poppet 27) which intersects the poppet plate 271 shownin arcuate form in FIG. 21. The ve poppet stations correspond to thefive positions of the valve 230 of FIG. 17. The poppet carrier isattached tot iarm 262 of shaft 25%. When handle 250 rotates hollow shaft258 of FIGS. 20 rand 21, the arm 262 rotates the poppet carrier 269, thepoppet 270 ratcheting over fixed plate 271, resisting the motion at thefive cam positions shown. I

The master operator control handle 250 of FIG. 20 is supported infitting 251 and has a ball joint 252, the inner end of handle 250engaging plunger 253 urged by spring 254 to project `a pin at the end ofthe plunger into guide recesses 255 formed under the sector plate 257.The handle 250 has limited rocking motion in planes including the axisof the steering column 256, and also rotates the shaft 25S by thefitting 251. The pointer 261 is ixed to the litting 251, and moves underthe transparent or translucent window marked P.N.D.L.R. of the sectorplate 257, in FIG. 22.

The lower end of the shaft 253 is fastened to arm 262 of FIG. 20 pivotedto bent Aarm 263, the other end portion of which pivots in the short armof bell-crank 1ever 264.

Referring back to FIG. 19 it will be seen that lever 264 is supported onthe frame, and is pivoted to rod 265 pivoted to the arm 174 of shaft173.

The handle 250 is arranged to have sector motion so that its stationswill appear on the indicator sector 257 of FIG. 22 which is markedP-N-D-L-R.

The handle 250 has planar or vertical motion so that it may be liftedfor establishing the shift to reverse.

The pin of sliding plunger 253 may travel freely from positions P to L,but it encounters stop 255 under the sector plate 257, requiring thehandle 250 to be lifted as shown, for retracting the plunger bolt 253against spring 254, to get into R position, for establishing reversedrive.

The arrangement prevents accidental shift to reverse, the stop action ofplunger 253 preventing further movement until the plunger is retracted.The stop 255 may talso be used to establish a similar dwell duringshiftin from reverse to forward. s

The described dwell-compelling mechanism located in the steering columncontroi head is related to the posi- 'conditions described in connectionwith FIG. 13.

lil? tions of the poppet 270 and plate 271 of FIG. 21, and once properlycalibrated, this mechanism stays put. Similarly, the follower motions ofthe rods and levers of FIG. 19 are coordinated with the positioning ofthe ratio control valve 230 of FIGS. l2 to 14 and 17, and the parkingbrake mechanism of FIG. 15, so that each of the stations of the pointerA261 over sector plate 257 of FIG. 22 corresponds exactly to theestablished control action.

, The station positions for the master ratio control valve 230 are shownin FIGURES 12, 13, 14 4and 17 by the notations N, Low, Rev. and High,the fth station PK in FIG. 19 being for the parking brake setting. Thevalve 2,30 continues tot block the feed ports 232 and 237 as in neutral,and the travel range of the valve 230 to the parking brake station ismerely to provide sufiicient motion for the required operation of theconstruction shown in FIG. 15.

The cooler C of FIG, 16 is located between passages 165V and 165'. Thetorque converter W' during normal operation generates a variablepressure in the oil of its working space. The detail of the coolerconstruction is not shown but the invention contemplates restrictedcooler passage-s to assist in stabilizing the flow of working sp acelluid against fluctuations caused by oil temperature variations and bysurges in converter generated pressure. The pump system, controlled bypressure regulator Valve 150 provides a reasonably steady ilow, to theconverter working space.

In view of the above detailed description of the operations, it is notdeemed necessary to repeat them in detail. After starting the vehicleengine, with the handle 250 of FIGS. 20 and 22 moved so that the pointer261 indicates neutral, the handle is then normally moved to drive,position D of the sector plate 257, which will cause the poppet 270 tomove into the position shown in FIG. 21 las shaft 258 is rotated, thismotion being transferred to lever 174 of FIG. 19, which is stationed asshown in that figure. For all normal driving purposes this simpleoperation serves to couple the direct drive clutch 40-45 of FIG. 1 sothat the torque converter W drives shaft 60 automatically at variablespeed ratio.

When it be desired to shift to low gear, and actuate band 50 toesetablish sun gear 3S as the gear reaction member, the handle 250 ismoved freely to the position L which shifts the ratio control valve 230,so as to establish the tluid pressure conditions described in connectionwith FIG. l2. If it be desired to shift freely between low and reverse,all the operator is required to do is to lift the end ofthe handle 25)while it is being moved to station the pointer 261 at the extreme rightposition of FIG. 22, this operation establishing the fluid pressure Thehandle 25) may be used for maneuvering a car out of a space wheretraction is uncertain, with facility.

The engine may be started with the handle in either neutral or parkingposition, since there will be no drive of the vehicle by the torqueconverter until the gear unit G establishes a driving couple with theoutput shaft oil. It will be noted that in making the hand shift fromdirect through neutral to the parking position, it is necessary to liftthe handle slightly in order for the pin end of the bolt 253 to clearone of the stops255. This feature serves to warn the driver whoseattention may be otherwise diverted from the sector plate and pointer261, so that the driver will be aware of the position ofhandle 25d byfeel.

The overall advantage of the present invention is the extraordinaryfacility provided the car driver for obtaining completely smoothacceleration from standstill to approximate -1-to-1 drive, withouttorque interruption, as well as the ability to change from one drivingrange to another during such acceleration, and with the drive mechanismso controlled that there is, no effective interruption of the driveduring such shift transition from either range to the other. Furtheradvantages provided by the construction and the combinations embodiedherein are likewise obtained in the extra facility for changing thedrive between forward and reverse, and for actuating a parking brake bythe same mechanism utilised by the driver for controlling the otherdrive conditions.

It is not believed that heretofore in this art there has appeared atorque converter and gear drive combination which possessed the abilityto permit full torque shift between two driving ratio ranges over thecomplete scale of torque converter drive ratio extending from initialreduction to approximate l-to-l top ratio, with the facility for freechoice between the two ranges by the driver.

The application of the invention may obviously take many forms, andtherefore, while this specification has described and illustrated onepractical and useful embodiment of the combinations of the invention, itis to be understood that the invention is in no way limited to theconstructional details given herein, and that the invention may bevaried within the scope of the following claims.

I claim:

l. In a liquid pressure actuator device for a variable speed ratiotransmission or the like, a clutch housing supported for rotation aboutits axis and having a fluid pressure chamber, a piston in said housingadapted to be urged in one direction by pressures of the liquid in thechamber, a release spring adapted to urge the piston in the oppositedirection, friction clutch elements associated with said housing andpressed together on movement of said piston by liquid under pressure insaid chamber, a passage extending through a wall of said chamberadjacent the periphery of said chamber, and valve means controllingrelease of liquid from said chamber through said passage, said valvemeans being governed by movement of said piston so as to close saidpassage on movement of said piston against said release spring and toopen said passage on movement of said piston by said release spring.

2. A pressure actuator as described in the claim 1 and in which there isa control passage communicating with said chamber and through whichliquid under pressure may be supplied to and released from said chamber,said control passage communicating with said chamber adjacent theradially innermost portion thereof, a communication between said controlpassage and the atmosphere, and a check valve controlling saidlast-named communication so as to prevent ilow of liquid from saidcontrol passage and to permit ilow of air to said control passage.

3. In a transmission, an input member, an output member, planetarygearing for selectively establishing two driving speed ratios from theinput member to the output member, a clutch for establishing one ratio,a brake for holding a reaction member to establish the other ratio,fluid pressure actuator for said brake and clutch, a valve forselectively controlling the supply of fluid under pressure to, and therelease of fluid from said actuators, an orice in the connection betweensaid valve and one of said actuators for limiting the rate of supply ofliuid under pressure to said one actuator, and valve means operative inresponse to torque reaction on said brake member in excess of a selectedamount to establish a communication extending around said orificethrough said connection.

4. In a power transmission, an input member, an output member, afriction torque-establishing device for establishing a drivingconnection between members, a iuid pressure actuator for said device, acontrol passage through which fluid under pressure may be supplied tosaid actuator, and means for regulating the rate of change in thepressure of the fluid in said actuator, said means comprising an orificein the passage for limiting the rate of iiow 0f fluid through saidcontrol passage, a by-pass conduit around the orifice, a chamberconnected to said passage between the oriiice and the actuator in whichthere is slidable a piston subject to the opposing forces of a springand of pressure of iiuid in said chamber, said piston being urged bysaid spring to open the oy-pass and being El movable against said springto close the by-pass in response to pressure in the chamber.

5. A transmission as described in claim 4, in which there is a secondby-pass around said orifice, a check valve in the second by-passoperative upon the fluid outflow from said actuator to open the secondby-pass.

6. In a power transmission, an input member, an output member, afriction device operative in accordance with the pressure of the huid ina chamber to establish driving connection between said input and outputmembers, a control passage through which fluid under pressure may besupplied to and released from said chamber, a control valve selectivelyoperative toI connect said control passage to a source of duid underpressure and to exhaust, and means for regulating the rate of flow ofHuid to and from said chamber through said control passage, said meanscomprising an orifice limiting the rate of flow of fluid through saidcontrol passage, a first valve operative on a selected increase in thepressure of the iuid in said chamber to cut off supply of iiuid to saidchamber through a rst by-pass extending around said oriiice, a checkvalve operative to permit fluid to flow from said chamber through asecond by-pass extending around said orifice, and an accumulatorconnected with said control passage at a point intermediate said orificeand said chamber` 7. A transmission as described in claim 6 and in whichthe accumulator comprises a variable capacity container having a movablewall positioned by the opposing forces of a spring, and of the fluid inthe portion of said control passage intermediate said orifice and saidchamber.

8. In transmission ratio controls for fluid-pressure actuated changespeed gearing, driving and driven shafts, the combination or" a gearunit including forward and reverse drive gearing connecting said shaftsand having a plurality of individually energized actuators forestablishing selected gear ratios of said unit, a fluid pressure supplysystem including a plurality of pumps driven by said shafts and adaptedto furnish fluid pressure for said actuators, said forward and reversedrive gearing, of said unit being made operative by said actuators, amaster control valve operative to distribute the fluid pressure of saidsystem selectively to said actuators for providing said forward andreverse drives, a casing for said gearing, a shifter shaft in saidcasing adapted to move the said valve, an external lever on said shaft,a vehicle steering column and a ratio control shaft supported thereinfor rotational motion, mechanical connections between said control shaftand said lever for transmitting the rotational motion of said controlshaft to said casing-mounted shifter shaft for moving said mastercontrol valve to predetermined inoperative and pressure deliveringpositions for energizing selected ratio actuators, a control head membermounted on said column and connected to rotate said control shaft, anoperator handle supported in said head for rotating said control headand shaft and for limited rocking motion in the axial plane f saidcontrol shaft, and stop mechanism operative to permit a range of freerotational motion of said head but preventing same for a predeterminedpositioning of said handle except .the handle to lbe moved in thedirection of said rocking motion.

9. In the combination set forth in claim 8, the subcombination of abrake member for said driven shaft, and a cooperating member for holdingsaid brake member, a linkage between said cooperating member and saidshifter shaft arranged to render same operative to hold said brakemember, and an arrangement of said handle, said control shaft, saidconnections, and said shifter shaft, operative for a given position ofsaid handle when said valve is inoperative, to so hold said cooperatingmember.

10. In the combination set forth in claim 8, the subcombination of apoppet mechanism connected to said control shaft, for establishing arotational series of dwell positions for said handle and said controlshaft, and a 22 movable stop for the said handle and control shaftrequiring rocking of said handle for shift of the poppet mechanism to anend dwell position of said handle.

11. In a uid pressure ratio-changing system for power transmissionshaving driving and driven shafts, a plurality of members actuable forestablishing a range of forward and reverse speed ratio drives, apluralityof uid pressure actuators for said members, individual actuatorfeed passages for each of said actuators, a plurality of fluid pressuresupply passages, a fluid pressure control arrangement consisting of avalve casing having inlet ports connected to said supply passages, aplurality of delivery ports connected to said feed passages, and aplurality of exhaust ports, and a master ratio control valve located ina bore in said casing, and movable to provide individual delivery of thepressure supplied said inlet ports to each of said delivery portsconnected to said actuator pas sages while connecting all other of saiddelivery ports to said exhaust ports; the arrangement of said valve withrespect to the said ports being such that in one position of the valvethe said plurality of inlet ports are blocked, and said delivery portsare connected to said plurality of exhaust ports.

12. The combination set forth in claim 11 having a parking brakemechanism including a locking member actuatable for holding said drivenshaft from rotating, a controller effective to move said Vcontrol valveand adapted to set the locking member to hold the driven shaft when saidvalve is set in another position in which the valve continues to blocksaid inlet ports, while exhausting said feed ports.

13. A power gear unit including a direct drive clutch for connecting twoof the gear unit members, a pistonand-cylinder forming a clutchactuator, a reaction brake for one'of said members operative toestablish low gear drive by said unit, a piston-and-cylinder actuatorfor said brake, a first pressure feed passage for said clutch-actuatorcylinder, a second pressure feed passage for said brakeactuatorcylinder, a pressure control device in said first passage operative toprovide rapid filling of said clutchactuator cylinder and to providerapid venting thereof, a pressure control device in said second passagefor said brake-actuator cylinder, a master control valve movableselectively to deliver tiuid under pressure to one of said passageswhile venting the other passage, and a torqueresponsive controlmechanism, responding to the torque reaction of one of said gear unitmembers and connected to said passages, automatically effective toregulate the transition from drive determined by pressure supplied bysaid valve to one of said passages, to drive determined by pressuresupplied to the other of said passages.

14. The combination set forth in claim 13, having an accumulator valvenormally biased by a spring, and connected lto one of the said cylindersfor permitting rapid filling flow thereof from the said control valve,and movable by the pressure developed in said cylinder to restrict thesaid flow, and a pilot valve and spring, responsive to said developedpressure, operative to augment the release of fluid from said cylinderwhen said control valve is moved to connect one of said cylinders toexhaust.

15. The combination set forth in claim 13, having vone end of saidreaction brake movable by said brake piston, and the other end thereofresiliently supported for anchor reaction by a torque-measuring valveand spring, with porting for said valve, to constitute the saidtorqueresponsive control mechanism, and passages connecting saidtorque-measuring valve with said first named feed passages such that theaforesaid transition control is made effective.

16. In uid pressure-actuated controls for step-ratio gear units, a gearunit coupling driving and driven shafts, a reaction brake for said uni-thaving one end thereof actuated by an actuator piston, and a movableanchor end, a l to 1 coupling clutch for said unit having an actuatorpiston, cylinders for said pistons connected to two duid pressure feedpassages, a valve normally raised into

37. A VARIABLE SPEED POWER TRANSMISSION MECHANISM COMPRISING THECOMBINATION OF A HYDRAULIC TORQUE CONVERTER AND AN EPICYCLIC GEAR UNITEQUIPPED WITH FLUID PRESSURE ACTUATORS, A COMMON PRESSURE SUPPLY SOURCEFOR SAID CONVERTER AND SAID ACTUATORS, CONTROL VALVING OPERATIVE FORMAINTAINING FLUID PRESSURE IN THE WORKING SPACE OF SAID CONVERTER AT AGIVEN PRESSURE, AND SUPPLIED FROM SAID SOURCE, LUBRICATION DELIVERYPASSAGES CONNECTED TO SAID SPACE AND TO SAID SOURCE, A PLURALITY OFPRESSURE DELIVERY PASSAGES FOR SAID ACTUATORS, SAID LATTER PASSAGESBEING SUPPLIED FROM SAID SOURCE, SELECTOR VALVING OPERATIVE TO SELECTTHE DELIVERY OF SAID PRESSURE TO SAID ACTUATOR